Sceptic Links Discussion

[Devonian]

Fair enough Dev, I posted it for scrutiny and to raise awareness, I've achieved both so I'm happy and no doubt I'll post more links/papers which you and I will disagree upon; that's life. You are happy with the IPCC stance, I'm not. I began this journey of learning from a believer in the general idea of AGW, the more I've read, the more I've learnt, the more I see there are reasons for concern, doubt and questioning; whilst that remains I'll continue to ask and challenge. Never in my wildest dreams would I ever imagine you and I will ever agree, you always appear a black/white kind of guy in this debate, I'm more of a grey area in the middle kind of gal.

Well, to me you about as certain a sceptic as I've ever come across :lol:

Me? Yup I'm black and white, that's why I think anthro warming will probably be in the 2-4C range...

[jethro]

Well, to me you about as certain a sceptic as I've ever come across :blink:

????? Do you actually read what I say? All the way down the line I've stated time and again that yes the climate has changed/is changing, that dumping and polluting the planet is not a good thing, in whatever form that takes whether it be Co2 or fly-tipping. I've held my hand up and said mankind is undoubtedly responsible for some of those changes, I've advocated increased taxation to curb consumerism etc. All I've ever said from a sceptic viewpoint is I am not convinced it is all down to mankind and increased Co2 emissions; the blinkered IPCC stance is misleading and ultimately dangerous to hundreds of thousands if the natural forces they so easily dismissed are of greater magnitude than they accredit them with. I suggest you go back and read again, at no point have I ever said "hey it's all baloney", I've always said "er, what about this, doesn't this count towards the warming".

[Eli Rabett]

,

EG Beck wrote:

I don´t understand your problem. Please read my paper and look at the graphs. I have evaluated all locations inclusive all possible influences. I have not excluded any. There is no dispute: Giessen was a continental station with all it´s influences as e.g. Schauinsland. At Schauinsland ( southern Germany, ner the city of Freiburg) they process data to get fanatstic background level.

http://archiv.ub.uni-heidelberg.de/volltex...midtJGR2003.pdf

The brownstone mining is the only industry near Giessen with sampling brownstone on the surface. No industrial processing but transporting raw matrial to the Ruhrgebiet. Kreutz hat clearly shown the influence from south-west direction in his wind diagram.

You have read that paper and the one from the same group in Tellus (1996)? If you had you could have realized a couple of things. First Schauinsland is about 1000 m high and looks out over the Rhine valley. The Giessen station, on the other hand is surrounded by hills.

The Regierungsbezirk of Gießen was created in 1981 from areas formerly belonging to the Regierungsbezirke of Kassel and Darmstadt. With an area of 5 381 km², it is the smallest of Hessen's three Regierungsbezirke and includes the Landkreise of Gießen, Limburg-Weilburg and Marburg-Biedenkopf, and the Kreise of Lahn-Dill and Vogelsberg. The region is ringed by hills, from the Taunus und Westerwald in the west to the Vogelsberg in the east. To the south the region gives way to the Wetterau.

At night Schauinsland station is above the boundary layer inversion of the Rhine valley, during the day not, so published measurements at Schauinsland were taken ONLY AT NIGHT and only for wind speeds above 2.5 m/s. You cannot say the same thing for Giessen. The Giessen measurements were in the middle of an agricultural research station where changes in plant respiration through the year and day were large. Schauinsland was identified as a place where the position and meteorology isolated the measurements from local influences under certain conditions.

In order to remove locally influenced data from those representative for a larger area over the European continent, we perform a selection procedure on the Schauinsland CO2 and 222Rn measurements which was previously described by Schmidt et al. [1996]. To avoid source/sink influence from the Rhine valley through upslope winds during the day, we use only nighttime values (2200–0600 LT) and select situations with high wind speed (>2.5 m sec1 in summer and >3.5 m sec1 in winter). The calculated daily mean CO2 mixing ratio is finally accepted if more than 8 half hourly values have been selected and the CO2 standard deviation of these 8 or more values is smaller than 1.5 ppm. On average 87 ± 21 days per year satisfy this selection criterion between 1972 and 2001. The selected data are distributed almost evenly between all months with July and August data being slightly underrepresented (July/ August 5.5%, all other month 7–10%). We employ a curve fitting procedure to the selected data described by Thoning et al. [1989] and Masarie and Tans [1995]. The curve fit incorporates harmonic and quadratic functions, and an 80-day smoothing is applied to the residuals. A 3-sigma filter is applied in the smoothing process to obtain the bestfit curve, excluding statistical outliers.

In short, at Schauinsel measurements representative of CO2 in Europe could be isolated from local influences. This says nothing about Giessen which pretty clearly is not an ideal place for such measurements.

[jethro]

Found this, it's an interesting read.

http://icecap.us/images/uploads/Lockwood_a...lich_Review.pdf

[Devonian]

From the sceptic link thread:

Apparently the IPCC haven't made any climate predictions, apparently they are just "what if" projections... And this guy should know, he was closely involved.

http://www.news.com.au/couriermail/story/0...4-27197,00.html

Was he 'closely involved'? If he was he was the only geologist who was 'closely involved' with climate modelling and the IPCC?

I'd like to see the proof he was 'closely involved'

[jethro]

From the sceptic link thread:

Was he 'closely involved'? If he was he was the only geologist who was 'closely involved' with climate modelling and the IPCC?

I'd like to see the proof he was 'closely involved'

http://www.cgd.ucar.edu/cas/trenbert.html

http://www.esi-topics.com/gwarm/interviews...nTrenberth.html

http://en.wikipedia.org/wiki/Kevin_Trenberth

http://democrats.science.house.gov/Media/F...h_testimony.pdf

[The PIT]

oh lovely another source to argue if its right or wrong. Head withdrawn below parapet again!

Got room for another John???

I'll let the Highly Qualified Skeptics and Highly Qualified Pro Warmers battle out until the keyboards pack up.

[Devonian]

http://www.cgd.ucar.edu/cas/trenbert.html

http://www.esi-topics.com/gwarm/interviews...nTrenberth.html

http://en.wikipedia.org/wiki/Kevin_Trenberth

http://democrats.science.house.gov/Media/F...h_testimony.pdf

Ahh, I thought you meant Bob Carter - it was, after all, he who wrote what you linked to!

[jethro]

Ahh, I thought you meant Bob Carter - it was, after all, he who wrote what you linked to!

Sorry you misunderstood, I thought the opening sentence "Kevin Trenberth" would be self-explanatory; I should have made myself clearer. Although the link I posted was an article by Bob Carter, not a darling of the AGW camp; it was accurate reporting. Here is another link, the statement by Mr. Trenberth actually went further than Bob Carter reported, if anything the full statement is even more damning of the concept that the IPCC have all the answers.

http://blogs.nature.com/climatefeedback/20...of_climate.html

[eddie]

To be fair to the IPCC can only ever offer 'what if' projections because they don't know how much C02 we are going to release.

I don't think using 'what ifs' invalidates what they are trying to do (even if I don't necessarily agree with their numbers).

[jethro]

To be fair to the IPCC can only ever offer 'what if' projections because they don't know how much C02 we are going to release.

I don't think using 'what ifs' invalidates what they are trying to do (even if I don't necessarily agree with their numbers).

Yes, but that's not what they are doing or being held up by the world at large as doing. The IPCC are lauded far and wide as having all the answers, governments the world over are, or are being urged to address their Co2 output based on the findings of the IPCC report. Any sceptic question/doubt is measured against this report, it is supposed to be the benchmark against which climate science is judged. Their inaccuracies are not as a result of not knowing Co2 emissions, if they were I wouldn't have a problem with it. I and others on here have said time and again correlation does not equal cause, 3+2=5 as does 2=2+1 etc, yes Co2 emissions have increased, yes global temperatures have increased slightly; one does not necessarily follow the other in the way the IPCC has portrayed and neither are their predictions or "what if's" in any way accurate nor can they be based on current modelling. A sceptic voice raising these points or concerns is easily dismissed, someone who is not only an advocate of AGW but a learned one at that, involved in the actual process of this report, who thens turns round and says exactly the same thing, cannot so easily be ignored. The IPCC report has and has always had fundamental flaws.

[eddie]

Yes, but that's not what they are doing or being held up by the world at large as doing. The IPCC are lauded far and wide as having all the answers, governments the world over are, or are being urged to address their Co2 output based on the findings of the IPCC report. Any sceptic question/doubt is measured against this report, it is supposed to be the benchmark against which climate science is judged. Their inaccuracies are not as a result of not knowing Co2 emissions, if they were I wouldn't have a problem with it. I and others on here have said time and again correlation does not equal cause, 3+2=5 as does 2=2+1 etc, yes Co2 emissions have increased, yes global temperatures have increased slightly; one does not necessarily follow the other in the way the IPCC has portrayed and neither are their predictions or "what if's" in any way accurate nor can they be based on current modelling. A sceptic voice raising these points or concerns is easily dismissed, someone who is not only an advocate of AGW but a learned one at that, involved in the actual process of this report, who thens turns round and says exactly the same thing, cannot so easily be ignored. The IPCC report has and has always had fundamental flaws.

As far as I can see, in the article you linked, Kevin Trenberth is saying the science is not in a state to predict future local climate variations. He wasn't saying that there was any doubt over the fact that the the earth is warming due to AGW (or even by how much).

He was commenting on the fact that we will need to adapt to the effects of local climate change but doesn't think that the science is in a state to predict what they will be.

I do actually agree with you that the IPCC report is flawed (see this post I made a week or so back..... random rant about climate models) but I don't think it's flawed to the point where you can question whether AGW is real or not.

/edit: I should add that I even though I think AGW is real I do think they have underestimated the Sun a little.

Edited July 31, 2007 by eddie

[jethro]

As far as I can see, in the article you linked, Kevin Trenberth is saying the science is not in a state to predict future local climate variations. He wasn't saying that there was any doubt over the fact that the the earth is warming due to AGW (or even by how much).

He was commenting on the fact that we will need to adapt to the effects of local climate change but doesn't think that the science is in a state to predict what they will be.

I do actually agree with you that the IPCC report is flawed (see this post I made a week or so back..... random rant about climate models) but I don't think it's flawed to the point where you can question whether AGW is real or not.

/edit: I should add that I even though I think AGW is real I do think they have underestimated the Sun a little.

I don't think it's flawed to the point of AGW being unreal, but I do think understanding AGW and its' ramifications is utterly impossible unless natural drivers are more fully understood, how these all interact and how adding Co2 changes the natural flow of the climate. Once you know all these or at the very least, are a whole sight closer to understanding than we are now, and once the climate as it stands today is programmed into the models, then and only then will any IPCC predictions/likely outcomes/what ifs, stand any chance of being accurate. My concern is, and always has been that the focus on Co2 being the leading cause of climate change is a dangerous stance to take if other natural drivers are at work here. Any predictions based on this will be invalid and the forecast changes may be greater, happen quicker than we as a race are prepared for; with so many lives potentially at risk, the majority of which, from the poorer less developed countries who are less able to adapt, I for one think we have a moral duty to make damn sure we've got it as right as we possibly can. I don't think we're anywhere near.

[eddie]

I don't think it's flawed to the point of AGW being unreal, but I do think understanding AGW and its' ramifications is utterly impossible unless natural drivers are more fully understood, how these all interact and how adding Co2 changes the natural flow of the climate. Once you know all these or at the very least, are a whole sight closer to understanding than we are now, and once the climate as it stands today is programmed into the models, then and only then will any IPCC predictions/likely outcomes/what ifs, stand any chance of being accurate. My concern is, and always has been that the focus on Co2 being the leading cause of climate change is a dangerous stance to take if other natural drivers are at work here. Any predictions based on this will be invalid and the forecast changes may be greater, happen quicker than we as a race are prepared for; with so many lives potentially at risk, the majority of which, from the poorer less developed countries who are less able to adapt, I for one think we have a moral duty to make damn sure we've got it as right as we possibly can. I don't think we're anywhere near.

Climate scientists aren't all going to pack up shop and hand over to the economists because they think their work is done now that IPCC 4 has been released. The science is still going to get refined and, even though it might be flawed, I don't think any goverment decisions based on IPCC 4 will cause much harm compared to indecision waiting for IPCC 5 or whatever comes next.

What if we can't program all the factors into the models? What if it is just not technically possible for the next ten or twenty years because computers are not yet powerful enough? At what point do we decide that the models are good enough to make some kind of decision?

[Admiral_Bobski]

At what point do we decide that the models are good enough to make some kind of decision?

I've pondered this question for a day or two so as to give what I feel to be a fair answer. So here it is.

Currently we have identified a number of climate forcings, of which Greenhouse Gases are one. Others include Aerosols, Ozone, Water Vapour and Solar effects.

So far, we only have a High level of understanding of one of those forcings: Greenhouse Gases.

Of the others, of Ozone we have a Medium level of understanding, and of all the other forcings we have a Medium-to-Low or Low understanding.

In the interests of accuracy and fairness, I would say that we can deem the models to be accurate enough when we have an equal level of understanding of all of the various forcing factors.

CB

[HighPressure]

I've pondered this question for a day or two so as to give what I feel to be a fair answer. So here it is.

Currently we have identified a number of climate forcings, of which Greenhouse Gases are one. Others include Aerosols, Ozone, Water Vapour and Solar effects.

So far, we only have a High level of understanding of one of those forcings: Greenhouse Gases.

Of the others, of Ozone we have a Medium level of understanding, and of all the other forcings we have a Medium-to-Low or Low understanding.

In the interests of accuracy and fairness, I would say that we can deem the models to be accurate enough when we have an equal level of understanding of all of the various forcing factors.

CB

Hi CB

Having worked with models on a daily basis, my experience tells me that even if you have a full understanding of all the inputs unless you have an even fuller understanding of the interaction of all inputs the model output will carry a degree of inaccuracy which increases with time span. Models can only be used as one tool in an armoury not as a final solution to any problem until they can be shown to be able to recreate the past with almost 100% accuracy. Having spent hundreds of hours using known data and results in an effort to tweak models far less complex then climate ones and been unsuccessful in recreating the past, I believe that expert experienced human assimilation will win over a model every time.

[Admiral_Bobski]

Hi CB

Having worked with models on a daily basis, my experience tells me that even if you have a full understanding of all the inputs unless you have an even fuller understanding of the interaction of all inputs the model output will carry a degree of inaccuracy which increases with time span.

Hi HP!

Thanks for that - a very good point. Perhaps having an equal level of understanding of all the various factors is just the first of many, many steps on the road to accepting the accuracy of the models...

The bottom line is that the models are (or can be) useful tools, but they are only useful in conjunction with other factors.

CB

[Iceberg]

But the models are far less complicated than the models used for weather forecasting.

Take a very simple model of the earth and the sun, increase the power of the sun, the earth will warm up, yes you could add the forcing feedbacks etc, but they would just tweak the figure up and down. The earth will still warm up in them model.

Now very simply increase the amount of cloud, the earth will cool down again (probably!).

You don't have to include everything and every forcing to get a general feeling of what will happen.

The IPCC predictions are of 2 to 4.5C or something like that. This is a wide variation, yes the more we know about things the more tweaking will occur, but nothing is really going to alter the fact of sustained GW.

Reading too much into models is a worry and probably happens atm, they are there to show possible scenario's on a Global or semi-global scale.

I think anyway....

[Admiral_Bobski]

But the models are far less complicated than the models used for weather forecasting.

Take a very simple model of the earth and the sun, increase the power of the sun, the earth will warm up, yes you could add the forcing feedbacks etc, but they would just tweak the figure up and down. The earth will still warm up in them model.

Now very simply increase the amount of cloud, the earth will cool down again (probably!).

You don't have to include everything and every forcing to get a general feeling of what will happen.

The IPCC predictions are of 2 to 4.5C or something like that. This is a wide variation, yes the more we know about things the more tweaking will occur, but nothing is really going to alter the fact of sustained GW.

Reading too much into models is a worry and probably happens atm, they are there to show possible scenario's on a Global or semi-global scale.

I think anyway....

The "Hype" thread is going well at the moment with a less technical aspect to the discussion than many of us are used to ( ), so I thought I'd resuscitate this thread for those who may have a hankering for more technical discussions.

That said, I'm a bit tied up at the moment, so I'm not going to start a whole new subject for discussion, but I'll reply to Iceberg's post above.

The Climate models are far less complicated than the weather models... Perhaps the climate models need to be more complicated though. If the actual climate and its processes are complicated but the models are not then perhaps the models are missing something - perhaps even something crucial. Although a "Simple" model (and I use the word "Simple" meaning "Less complicated than reality" rather than what most would consider "Simple") may show clear trends, even trends we appear to be currently experiencing, continuing for the foreseeable future, they may be missing some important factor which will in reality alter those trends.

I suppose that, in the end, I'm disagreeing with Iceberg's view of the validity of the models, but I do agree that too much is read into the models, and too much emphasis is put on the models in terms of "proving" AGW theory (by which I mean that certain bodies say, effectively, that "the models say we're in big trouble so therefore we must actually be in big trouble).

What do people think? How much do people "trust" the models?

If you accept the models then can you explain why you do?

If you do not accept the models then can you explain your misgivings?

(This question is open to Techies and Laymen alike!)

CB

[parmenides3]

Hi, C-Bob: You are right that climate models contain fewer variables than NWP models, but this does not, of course, mean they are 'simple'.

We frequently discuss the possibility that these models might be 'missing something', but I'm still wondering what that something might be. Models aside, there is research ongoing on just about every imaginable element of the climate which is not model-dependent. There isn't much around at the moment which challenges the main principles of AGW.

The point is that the models are really just there to indicate trends, rather than replicate actual conditions. Given that most of the output is dependent on the laws of physics, scientists have varying degrees of confidence that they work okay for some things, whilst recognising that they don't model other things well. This doesn't mean they are broken, just that they could do some things better. For the big picture, the models appear to be very effective. Aha! you say... but perchance the devil is in the detail! I won't disagree; it may well be. Trenberth recently pointed out what Pielke Sr has been saying for a while now; for effective mitigation/adaptation policy, we need more and better RCMs.

When you say that 'too much is read into the models', this needs qualification; who reads too much? Is climate science too model-dependent? Big questions.

I trust the models are showing us a realistic set of trend patterns with a high degree of likelihood, especially in terms of global surface temperature trend. I do this, because there's so much scientific material around which supports this acceptance, and its logic is pretty sound. I probably also largely trust the models to project changes in the Hadley and Ferrell cell circulations with some reliability. Beyond that, I'd tend to deal with likelihood far more often than 'trust'.

My misgivings are that there is still the tendency for the media, and some press releases from agencies which should know better, to talk about model output as if its veracity is a given. It drives me nuts. Having said that, quite a bit of what the models project is little more than might be arrived at by commmon-sense, if the assumption of a continuing trend of warming is accepted.

:)P

[Admiral_Bobski]

Hi P3 (it's nice to see you back in the Environment Forum, BTW!)

Hi, C-Bob: You are right that climate models contain fewer variables than NWP models, but this does not, of course, mean they are 'simple'.

If I could refer you to my little caveat: " I use the word "Simple" meaning "Less complicated than reality" rather than what most would consider "Simple"" While I appreciate that climate models are not, in and of themselves, Simple constructs, they are simplified constructs, and perhaps - just perhaps - simplified constructs are not overwhelmingly accurate in a field as complex as climatology.

We frequently discuss the possibility that these models might be 'missing something', but I'm still wondering what that something might be. Models aside, there is research ongoing on just about every imaginable element of the climate which is not model-dependent.

That "missing something" could be data which are either partially or wholly missing, data which have been misattributed (i.e. some numbers are too big while others are too small) or even (although perhaps less likely) whole forcings which are as yet unknown or misunderstood. While there is an enormous amount of ongoing research, with our understanding being refined all the way, we are still only just beginning to learn about various aspects of the climate system and new surprises keep popping up.

There isn't much around at the moment which challenges the main principles of AGW.

Well, the main principle of AGW is that "humans put stuff into the environment which warms the environment, and as long as that goes on, the environment will continue to warm". This is basically pretty indisputable, but then it all comes back to a matter of degree. (As a mathematical analogy you could say, "if we start at zero and successively add ones then after a hundred iterations we will reach the number 100". However, if we start at zero and successively add 0.1 then after a hundred iterations we will only reach the number 10. If there is another factor (or factors) which successively adds a variable number then it becomes harder to distinguish the number that we are adding...)

When you say that 'too much is read into the models', this needs qualification; who reads too much? Is climate science too model-dependent? Big questions.

When both the media and (some) scientists make constant reference to the models (the IPCC, for example, give their range of expected warming based upon the output from models) then I would say there is a bit of model dependency going on. The big problem is that our only predictions (projections might be a better word) come from models, and since all suggestions for mitigation are based upon those predictions then we need to consider where the science itself actually stands. (Not wanting to get into a political argument again, but eventually all discussions seem to come back to it!)

Anyway, that's all I have time for right now so I'll hop back on later

CB

[parmenides3]

One of the interesting things about new things popping up, is that more of them seem to add to the evidence that we have some idea of what to expect, than question this. So the balance of evidence grows ever stronger, bit by bit...

Whilst it's true that some aspects of the climate system are still 'young' in terms of research and understanding, there are other aspects which have been understood for many years, and these form the foundations of most climate science.

This year in particular, there seems to have been an increasing acceptance in climate science circles for the evaluation of climate sensitivity at around 3C, maybe 2.8-9C. A lot of this is down to James Annan and Julia Hargreaves, who have done some outstanding mathematical, probabilistic and statistical work on calcualting the likely range of CS. OTOH, I'm probably biased about this, as James is one of the co-authors on my paper. I recommend a look at some of their work; I think it will appeal to your mathematical inclinations.

It only takes a quick look around the blogosphere to see that there are plenty of climate scientists who are uncomfortable with the mitigation/adaptation element of the AR4. This is not because of their confidence (or lack of it) in the models, but of the difference between their tendency to understand models as imperfect speculators, and the tendency of others to read model output as 'gospel'.

Perhaps now would be a good time to start a discussion on which parts of the models' output we think are more likely to be reliable...

:)P

[Admiral_Bobski]

One of the interesting things about new things popping up, is that more of them seem to add to the evidence that we have some idea of what to expect, than question this. So the balance of evidence grows ever stronger, bit by bit...

There are other things which pop up which could be perceived to cast doubt on AGW - I have seen more evidence crop up over the past year, but I think the actual balance of evidence has changed very little, if at all...

As for the models, which parts do you consider to be the most reliable? I wonder how easy it is to separate the model output into various different parts, since everything in climate is heavily inter-related - which is one of the reasons I have my doubts about the models' accuracy.

CB

[parmenides3]

I'll take a look at one of the recent Hadley runs and post a link, if I can, so we can have a baseline to start from. Probably tomorrow sometime.

:)P

[Admiral_Bobski]

I'll take a look at one of the recent Hadley runs and post a link, if I can, so we can have a baseline to start from. Probably tomorrow sometime.

:)P

Hi P3!

Have you had a chance to do this yet? It could lead to an interesting discussion about model accuracy...

CB